Especially, this invention concerns control method and magnetism disk system of filter property of analogue filters on the control method of analogue filters detailed description of the invention technology field which the invention belongs to.
The conventional technology is explained using FIG. 2 conventional technology. FIG. 2 showed analogue filters blocks, and it is composed of analogue filters of 10, transconductance control circuit of 19, digital to analog conversion vessel 205.about.208, registers of 12. And, analogue filters of 10 consist of transconductance amplifier 50.about.53, 54,56 capacity. Transconductance amplifier of 19 is composed of replica transconductance amplifier of 21, resistance of 22, reference voltage source 20,23, differential amplifier of 24, voltage-current translate circuit of 29. In the conventional filter control system of transconductance amplifier 50.about.53 which constitutes analogue filters of 10 by using digital analog converter circuit 205.about.208 in proportion to the value that it converted the reference voltage which was created in transconductance control circuit of 19 into the current at voltage-current translate circuit 30.about.33 and set in registers of 12 for this current. The lance conductance has been controlled. It seems to describe analogue filters control method at U.S. Pat. No. 5,572,163.